Several systems and techniques are known for electronically monitoring material assets. U.S. Pat. No. 7,151,454 to Washington, as an example, provides systems and methods that may be employed to visually locate and/or track objects equipped with active radio frequency identification (RFID) tags. The systems and methods may employ an articulated camera, such as closed circuit television or other suitable type of articulated camera, that is equipped with an antenna array.
U.S. Pat. No. 7,138,916 to Schwartz et al., as another example, provides a computerized system to inventory articles, and to locate and recover lost or stolen articles. The system applies an electronic tag to each article of a multiplicity of articles, or only to a valuable article, and employs a computer to maintain an inventory of all articles. Use is made of a global positioning system to locate a lost or stolen article as well as to track movements of the article. A history of the movement of the article may also be plotted on a map. An electronic geographic boundary area may also be placed around an article that can be used to emit a signal indicative of the article leaving the area.
U.S. Pat. No. 7,123,149 to Nowak et al., as yet another example, provides an integrated system for tracking assets and personnel associated with a work site. Personnel are equipped with tracking devices having at least geo-location capability. Assets are tagged with radio frequency identification (RFID) tags, which are interrogated at portals, by mobile scanners, or by personnel tracking devices having RFID reading capability. The tag readers and tracking devices are all in communication with a common “information backbone” and all data is delivered to, and processed by, a common command and control subsystem.